Great question though I've heard it perhaps better asked, WHY am I doing THIS?
The one oversight many entrepreneurs make in trying to define their business objectives, raise capital, get traction, build a team, etc. is WHY?
We often develop our understanding of the exit strategies available. We talk of just wanting to solve a problem. We get excited about the prospect of an acquisition (or even more exciting but incredibly unlikely, an IPO). But the goal that VCs pick up on, potential partners infer, those joining the team, is WHY as it pertains to what's in it for me?
Ultimately, the direction a new venture goes is dependent on the personal goal of the entrepreneur. Is this a lifestyle business in which they'll be satisfied with a steady stream of income? Is an exit at $10-$20M acceptable or do the founders want to hold out? Are you providing a service and plan to grow methodically and safely? OR is this a game changing innovation with global aspirations the likes of Google?
It's easy to look at the tech, business model, and potential and have AN answer to that question, but if your answer is inconsistent with that of the founders, you're going to mismatch expectations and have a challenge.